Bloodborne Pathogens. Preventing Transmission of Bloodborne Pathogens. Are transmissible in health care settings Can produce chronic infection Are often carried by persons unaware of their infection.
Preventing Transmission of Bloodborne Pathogens • Are transmissible in health care settings • Can produce chronic infection • Are often carried by persons unaware of their infection Bloodborne viruses such as hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV)
Potential Routes of Transmission of Bloodborne Pathogens Patient DHCP Patient DHCP Patient Patient
Factors Influencing Occupational Risk of Bloodborne Virus Infection • Frequency of infection among patients • Risk of transmission after a blood exposure (i.e., type of virus) • Type and frequency of blood contact
Concentration of HBV in Body Fluids HighModerate Low/Not Detectable BloodSemen Urine SerumVaginal FluidFeces Wound exudatesSaliva Sweat Tears Breast Milk
Estimated Incidence of HBV Infections Among HCP and General Population, United States, 1985-1999 HealthCarePersonnel General U.S.Population
HBV Infection Among U.S. Dentists Percent Year Source: Cleveland et al., JADA 1996;127:1385-90. Personal communication ADA, Chakwan Siew, PhD, 2005.
Hepatitis B Vaccine • Vaccinate all DHCP who are at risk of exposure to blood • Provide access to qualified health care professionals for administration and follow-up testing • Test for anti-HBs 1 to 2 months after 3rd dose
Transmission of HBV from Infected DHCP to Patients • Nine clusters of transmission from dentists and oral surgeons to patients, 1970–1987 • Eight dentists tested for HBeAg were positive • Lack of documented transmissions since 1987 may reflect increased use of gloves and vaccine • One case of patient-to-patient transmission, 2003
Occupational Risk of HCV Transmission among HCP • Inefficiently transmitted by occupational exposures • Three reports of transmission from blood splash to the eye • Report of simultaneous transmission of HIV and HCV after non-intact skin exposure
HCV Infection in Dental Health Care Settings • Prevalence of HCV infection among dentists similar to that of general population (~ 1%-2%) • No reports of HCV transmission from infected DHCP to patients or from patient to patient • Risk of HCV transmission appears very low
Transmission of HIV from Infected Dentists to Patients • Only one documented case of HIV transmission from an infected dentist to patients • No transmissions documented in the investigation of 63 HIV-infected HCP (including 33 dentists or dental students)
Documented Possible Dental Worker 0 6 * Nurse 24 35 Lab Tech, clinical 16 17 Physician, nonsurgical 6 12 Lab Tech, nonclinical 3 – Other 8 69 Total 57 139 Health Care Workers with Documented and Possible Occupationally Acquired HIV/AIDS CDC Database as of December 2002 * 3 dentists, 1 oral surgeon, 2 dental assistants
Risk Factors for HIV Transmission after Percutaneous Exposure to HIV-Infected Blood CDC Case-Control Study • Deep injury • Visible blood on device • Needle placed in artery or vein • Terminal illness in source patient Source: Cardo, et al., N England J Medicine 1997;337:1485-90.
Characteristics of Percutaneous Injuries Among DHCP • Reported frequency among general dentists has declined • Caused by burs, syringe needles, other sharps • Occur outside the patient’s mouth • Involve small amounts of blood • Among oral surgeons, occur more frequently during fracture reductions and procedures involving wire
Exposure Prevention Strategies • Engineering controls • Work practice controls • Administrative controls
Engineering Controls • Isolate or remove the hazard • Examples: • Sharps container • Medical devices with injury protection features (e.g., self-sheathing needles)
Work Practice Controls • Change the manner of performing tasks • Examples include: • Using instruments instead of fingers to retract or palpate tissue • One-handed needle recapping
Administrative Controls • Policies, procedures, and enforcement measures • Placement in the hierarchy varies by the problem being addressed • Placed before engineering controls for airborne precautions (e.g., TB)
Post-exposure Management Program • Clear policies and procedures • Education of dental health care personnel (DHCP) • Rapid access to • Clinical care • Post-exposure prophylaxis (PEP) • Testing of source patients/HCP
Post-exposure Management • Wound management • Exposure reporting • Assessment of infection risk • Type and severity of exposure • Bloodborne status of source person • Susceptibility of exposed person